1. Field of the Invention
This invention relates to a guide device for the delivery portion of a shape mill for rolling shapes such as H-beams, I-beams or channels, for example. The invention further relates to a device for simplifying guide rearrangement, which is required for each shape size when rolling shapes of different sizes, thus improving rolling efficiency.
2. Description of the Related Art
When rolling steels with a shape mill, a guide device is usually employed in order to guide the material to be rolled correctly to the rolls and to restrain web off-centering, differences in upper and lower flange depth, etc.
Such a guide device is arranged at the entry and/or delivery side of the shape mill and usually consists of a flange guide device for the vertical rolls and a web guide device for the horizontal rolls.
Japanese Patent Laid-Open No. 2-211908 discloses a flange guide device for vertical rolls, according to which the flange outer surfaces are guided by means of chock cover plates, and a web guide device for horizontal rolls, which, as shown in FIG. 6, consists of upper and lower web guides 2 which are adapted to guide the web portion 1a of an H-beam 1 while holding it between them.
Such a conventional web guide as described above, however, is intended for use at a fixed web width. Accordingly, it requires replacement each time the size of the H-beams is changed, which requires much labor. Further, it is necessary to stock a variety of different guide devices for different sizes, which is further disadvantageous from the economical point of view.
In view of this, the present applicant has proposed, in Japanese Utility Model Laid-Open No. 61-67907, a variable-width web guide device, which adopts web guides separated in the width direction to allow lateral positional adjustment in accordance with the roll width; this is done by means of right- and left-hand screws reversely threaded. With this variable-width web guide device, however, the amount of width adjustment is physically limited in terms of space, so that the guides have to be replaced for each different series of products. Further, it takes time to perform guide alignment with respect to the rolling rolls.
Japanese Patent Laid-Open No. 63-68204 discloses a guide device in which the distances between the web guides for guiding the web surfaces and the distance between the guide rollers for guiding the outer flange end surfaces are fixed. This technique is intended for a shape product exhibiting a minimum dimension between the web surfaces and the outer flange end surfaces, so that when the guide members have been worn to a considerable degree, or when the size of the object to be rolled is frequently changed, the distance between the web guides and the web of the shape becomes excessively large, making the guiding of the web surface unstable, which results in deterioration in shape.
Japanese Patent Laid-Open No. 64-2715 discloses a shaft supporting a taper roller guide formed as an eccentric shaft, which is rotated so as to adjust the distance between the web guide surface and the taper roller guide. In accordance with this technique, the web guides can be appropriately positioned in accordance with the degree of wear of the guide members and changes in the distance between the web surfaces of the shape and the outer flange end surfaces (hereinafter referred to as the "flange depth"). Because of its eccentricity, however, such an eccentric shaft presents a problem in terms of the way it is fixed. Further, there is a variation in the balance of force when adjusting the distance. In addition, because of the bending moment acting in response to the pressure load, the strength of the section where the shaft rotation is stopped becomes particularly inadequate. Moreover, since the eccentric shaft is of a stationary type, it has been impossible to adjust it in accordance with the flange depth, which varies for each pass in the on-line operation.